The present invention relates to disposable diapers for absorption and containment of bodily discharges.
Conventional disposable diapers comprise, in addition to a liquid-pervious topsheet facing the wearer's skin, a liquid-impervious backsheet facing away from the wearer's skin and a liquid-absorbent core interposed between these top- and backsheets, a pair of side flaps extending in a longitudinal direction outside transversely opposite side edges of the core, a pair of end flaps extending in a transverse direction outside longitudinally opposite ends of the core, a pair of tape fasteners attached to the side flaps in the rear waist region, respectively, so as to extend in the transverse direction and a target tape strip attached to an outer surface of the front waist region so that the tape fasteners may be releasably anchored on the target tape strip.
In general, to put the diaper on the wearer's body, the side flaps in the rear waist region are placed upon the side flaps in the front waist region from outside, followed by anchoring the tape fasteners on the outer surface of the target tape strip to connect the front and rear waist regions with each other. Thereupon the diaper is formed with a waist-hole and a pair of leg-holes. During use of the diaper, the movement of the wearer's body may cause the pairs of side flaps in the front and rear waist regions overlapping each other to shift from each other. Eventually, these side flaps may be distorted or curled up.
Japanese Laid-Open Patent Application No. 1988-256702 (hereinafter “Citation”) proposed a diaper characterized in that the outer surface of the side flaps in the front waist region and the inner surface of the side flaps in the rear waist region are respectively coated with an anti-slip agent. According to the disclosure of Citation, undesirable relative slip between the side flaps in the front waist region and the side flaps in the rear waist region can be sufficiently restricted by the anti-slip agent to make a relative shift between the respective pairs of side flaps difficult and to eliminate distortion as well as curling up of these side flaps. The diaper disclosed in Citation uses an adhesive, an acrylic anti-slip agent or a urethane sheet as the anti-slip agent.
However, the diaper disclosed in Citation is still accompanied with a problem such that the side flaps in the rear waist region coated with the anti-slip agent may stick to the wearer's skin as the respective inner surfaces of these side flaps come in contact with the wearer's skin. As a result, the wearer may experience a uncomfortable feeling. Even if the undesirable relative shift between the side flaps in the front waist region and the side flaps in the rear waist region is successfully prevented, the side flaps in the rear waist region sticking to the wearer's skin inevitably follow movement of the wearer's skin. Consequently, the side flaps in the front and rear waist regions may be shifted off from the relative position of these side flaps required for proper wearing of the diaper and the diaper may unintentionally slip down from its desired position.